The backstory to the adventure is the idea that the Greek goddess Athena was once alive and served by a group of fighters called the Saints. The series proposes a concept called the Cosmos, in which each microscopic component of a human's body is equivalent to a solar system and that each collection of these solar systems (a human) comprise a small universe or Cosmos. Each person's Cosmos has unique properties and attributes and represents an internal spiritual essence.
The main character in the series is Seiya, who is introduced as a 13-year -old orphan with a long-lost sister. Seiya has been training in battle to become the "Knight of Athena" in the Galactic Tournament. After going on a quest to acquire the bronze armor of Pegasus and becoming the Pegasus Saint, Seiya meets up with her "brothers," other Bronze Saints, who have similar powers to fight against the world's evil and protect the incarnation of Athena, here called Saori Kido. Seiya and friends do this by realizing that by understanding their personal Cosmos. they can use the power behind them to perform fantastic feats. Each Saint wears the Cloth, armor that protects them, with each individual cloth correlating to constellations that serve as personal guardians to the saints.
The manga was first published by Shueisha in Japanese, Viz Media in English and Kana and Panini Comics in French. Spanish translations were licensed by Editorial Ivrea, Glenat Esoana and Grupo Editorial Vid, German editions by Planet Manga, Portuguese versions by Conrad and a Chinese copy by Ching Win Publishing.
The TV version ran three seasons from 1986 to 1989. The original Japanese version was produced by Toei Animation and translated into English, French, Spanish, Italian, Portuguese, German and Chinese. The films released were "Evil Goddess Eris" (1987), "The Heated Battle of the Gods" (1988), "Legend of Crimson Youth" (1988), "Warriors of the Final Holy Battle" (1989) and "Heaven Chapter: Overture" (2004).
A spin-off manga series has been released, including the prequel "Saint Seiya: The Lost Canvas." A TV spin-off "The Hades Inferno Chapter" ran 20 episodes and is considered by some to be part of the series. A live musical and various video games have been produced.